ACTG 373 - A Phase II Study of 1) 141W94/VX-478 plus 3TC plus ZDV or 2) Indinavir plus Nevirpine plus 3TC plus Stavudine in Subjects Previously Treated with 141W94/VX-478. The hypotheses are 1) that HIV-1 infected individuals who have responded to a regimen of zidovudine (ZDV), lamivudine (3TC), and 141W94/VX-478 with a drop in plasma HIV-1 RNA levels to <500 copies/mL can be maintained at or below that level for up to 96 weeks; and 2) that HIV-1 infected individuals who have been treated with a regimen containing 141W94/VX-478 but whose plasma HIV RNA levels have not fallen below 500 copies/mL, or who initially responded with a fall to below 500 copies/mL but whose virus has risen to >5000 copies/mL, or who are intolerant of a 141W94/VX-478 containing regimen will have plasma HIV-1 RNA levels driven to <500 copies/mL by a regimen of stavudine (d4T), 3TC, indinavir (IDV), and nevirapine (NVP). Subjects will receive one of two treatment regimens: ARM A: (Subjects with <500 copies HIV-1 RNA/mL on a regimen containing 141W94/VX-478): 141W94/VX-478 1200 mg q 12 hrs plus ZDV 300mg q 12 hrs or d4T 40mg q 12hrs* plus 3TC 150mg q 12 hr; ARM B: (Subjects with >=500 copies HIV-1 RNA/mL or intolerance to a regimen containing 141W94/VX-478): IDV 1000mg q 8 hrs plus NVP 200mg bid** plus 3TC 150mg bid plus d4T 40mg bid (For persons weighing <60kg, d4T 30mg BID will be administered.) *Subjects intolerant to ZDV may elect to receive d4T. **NVP 200mg will be administered once daily day 1-day 14, then bid thereafter. Subjects enrolled to ARM A who fail treatment therapy have the option of rolling over to ARM B. Subjects in ARM B who fail therapy will discontinue study medications and seek best available treatment.